Electrode-shield for vapor electric apparatus.



S. W. FARNSWORTH, D. E. CARPENTER, L. E. FROST, D. H. ROSE & E. F.SIPHER.

ELECTRODE SHIELD FOR VAPOR ELECTRIC APPARATUS.

APPLICATION FILED FEB. 2I. 1914.

1,159,916. Patented Nov. 9, 1915.

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ATTORNEY UNITED STATES PATENT oEFioE.

SIDNEY W. FARNSWORTH, OP PITTSBURGH, DAVID E. CARPENTER, OF WILKINSBURG,

LESLIE E. FROST, OF PITTSBURGH, ANDv DONALD H. ROSE AND EDMUND F.SIPHER, OF WILKINSIBURG, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRODE-SHIELD FOR VAPOR ELECTRIC APPARATUS.

Specification of Letters Patent.

Application filed February 21, 1914. Serial No. 820.197.

To all whom it may concern Be it known. that we, SIDNEY W. FARNS-won'rn, DAVID E. CARPENTER, LEsLIE E. Fnos'r, DONALD H. Ross, and EDMUNDF. SIPHER, citizens of the United States, and residents, respectively,of Pittsburgh, Wilkinsburg, Pittsburgh, Wilkinsburg, and Wilkinsburg, inthe county of Allegheny and State of Pennsylvania, have invented a newand useful Improvement in Electrode-Shields for Vapor ElectricApparatus, of which the following is a specification.

Our invention relates to electrode shields for vapor electric apparatussuch as current rectifiers of large capacity, and it has for its objectto provide a shield so constructed as to prevent short circuiting withinthe apparatus.-

In the, accompanying drawing, Figure 1 is a vertical sectional view,showing a ortion of the casing of a metal case rectifier and one of theanodes of the rectifier equipped with our invention, and Fig. 2 is ahorizontal sectional view through a metal case rectifier having threemain anodes, the section being taken on a plane corresponding to theline IIII of Fig. 1.

In vapor rectifiers of high capacity, it is now customary to inclose aplurality of anodes within a single casing, which may be of metal, andto provide a body of mercury or other vaporizable conducting vmaterialwhich serves as the common cathode for the anodes. In order to preventshort circuiting between the anodes, and the consequent interruption ofthe rectifying process, it is necessary to surround each anode with ashield, and We have performed numerous experiments to determine the bestform of such shields.

\Ve have discovered that the best results are obtained by employing theform of shield shown in Fig. 1 of the drawing, which shows atv 1 aportion of a rectifier casing within which is suspended an anode 2having a stem 3 which extends through the cover (not shown) of therectifier and is supported therein in any convenient manner. The anodeis surrounded by, and inclosed in, a shield or casing 4, which may be ofsubstantially cylindrical shape, one end being reduced in diameter andbeing secured to the cover of the rectifier by any suitable means.

The shield extends into the rectifier casing a considerable distancebeyond the end of the anode and has a closed inner end 5.

The sides of the shield, near the closed end 5, are provided with anumber of apertures 6 one of which, (5, is much larger than theremalnlng apertures. It will be observed that the large aperture 6 is atthe side of the shield nearest to the wall of the casing and that all ofthe perforations are below the end of the anode 2. \Ve find that thisarrangement of perforations is highly advantageous.

Fig. 2 shows the relative arrangement of a plurality of electrodeshields within a single casing. Thethree shields 4 are symmetricallydisposed about a central keepingalive electrode 7, the three mainelectrodes, of course, being correspondingly disposed. The shields areso positioned that the large opening (3 in each electrode shield is onthe side facing away from the keeping-alive electrode and nearest thecasing, While the smaller apertures 6 are symmetrically dis- PatentedNov. 9, 1915.

shield, some of these perforations facing the other shields, whileothers face the keepingalive electrode and still others occupyintermediate positions.

,In the appended claims, the term closed, as applied to the electrodeshield, is intended to include all such structures as are closeds'ufliciently to prevent the free passage of an are through the bottomof the shield, whether such closure is absolutely tight or not. It isalso to be understood that the expression of like polarity in certain ofthe claims refers to structures which have a plurality of electrodeswhich are the same in function, whether such electrodes are constantlyof the same polarity or not.

\Ve prefer, at present, that the shield be constructed of sheet metal,although shields formed of other materials are also comprehended withinthe scope of our invention.

We are at present unable to state the theoretical reasons for theimproved rectifier operation produced by our form of shield. However, wehave demonstrated the importance of the structural details herein shownand described by a series of experiments extending over a period of manymonths and consuming, in the aggregate, several thouthe electrodeshield, and, as a result of our.

investigations, we have fixed upon the form of shield herein set forthand claimed as being the best form which we have as yet been able todevise.

We claim as our invention:

1. An electrode shield comprising a sub-" stantially. cylindrical casinghaving a closed end and having perforations in itssides near the closedend, one of the said perforations being larger than the otherperforations. 7

2. A vapor electric device comprising a casing, an electrode extendinginto the casing, and a shield surrounding the electrode and extendinginto the casing farther than the electrode, the shield having a closedend and having a plurality of apertures in its sides below the end ofthe electrode, one of the apertures being larger than the otherapertures.

3. A vapor electric device comprising a casing, an electrode extendinginto the easing near one of the walls thereof, and a shield surroundingthe electrode and extending into the casing farther than the electrode,the shield having a closed end and having relatively small apertures inits sides near the closed end, and a relatively large aperture in itsside nearest the wall of the casing.

4. vapor electric device comprising a plurality of anodes symmetricallydistributed about a central keeping-alive electrode, each anode beingsurrounded by a cylindrical shield, the said shield being provided witha large opening on the side facing away from the keeping alive electrodeand with smaller openings in the portions of the shields facing eachother, such smaller openings being located below the lower end of theanode.

5. A vapor electric device comprising a casing, a plurality ofelectrodes of like polarity therein, and a shield for each of saidelectrodes provided with a relatively large opening facing away from theother electrodes, and with another and smaller opening.

6. A vapor electric device comprising a casing, a plurality ofelectrodes of like polarity therein, and a shield for each of saidelectrodes provided with a relatively large opening facing away from theother electrodes, and with a plurality of smaller openings. i

7. A vapor electric device comprising a casing, a plurality ofelectrodes of like po- 8. A vapor electric device comprising a casing, aplurality of electrodes of like polarity therein, and a shield for eachof said electrodes provided with a relatively large opening facing awayfrom the other elec trodes, and with a plurality of smaller-openings,the openings being located below the level of the end of the electrode.

9. A vapor electric device comprising a casing, a plurality ofelectrodes of like polarity therein, and a shield for each of the saidelectrodes rovided with a relatively large opening acing toward thecasing, and with another and smaller opening.

10. A vapor electric device comprising a casing, a plurality ofelectrodes of like polarity therein, and a shield for each of saidelectrodes provided with a relatively large opening facing away from theother elec-' trodes, and with a plurality of smaller openings, certainof said smaller openings facing each of the other electrodes, respectively.

1].. A vapor electric device comprising a casing, a plurality ofelectrodes of like polarity therein, and a shield for each of the saidelectrodes provided with a relatively large opening facing toward thecasing, and with a plurality of smaller openings.

12. A v'apor electric device comprising a casing, a plurality ofelectrodes of like polarity therein, and a shield for each of the saidelectrodes provided with a relatively large opening facing toward thecasing, and with another and smaller opening, the openings being locatedbelow the level of the electrode. 7

13. A vapor electric device comprising a casing, a plurality ofelectrodes of like polarity therein, and a shield for each of the saidelectrodes provided with a relatively large opening facing toward thecasing, and with a plurality of smaller openings, all of the openingsbeing located below the level of the end of the electrode.

In testimony whereof, we have hereunto subscribed our names this 16thday of Feb, 1914.

\Vitnesses:

B. B. HINES, E. E. Ross.

